Set Joint Acceleration

SUMMARY

Set Joint Acceleration sets the default joint acceleration used by motions that are called without an explicit acceleration. The initial value is 80 deg/s².

UNITS

acceleration is in deg/s² of the leading axis.

The Skill

robot.set_joint_acceleration(40.0)

The Code

Safety first!

A real robot will faithfully do whatever you ask of it - so please take a moment to clear the workspace, keep an E-Stop within reach, and be ready to disconnect.

Operating real hardware is at your own risk.

"""
Set the default joint acceleration, then make a joint move that uses it.

Supports Universal Robots (UR), Epson, virtual, and Isaac Sim.

Usage:
    python set_joint_acceleration.py [--ip <ROBOT_IP>] [--prim_path <PRIM_PATH>]
"""

import argparse

from loguru import logger

from telekinesis.synapse.robots.manipulators import universal_robots


def main(ip: str | None, prim_path: str | None) -> None:
    """Set the default joint acceleration and move with it."""

    #===================== Create Robot ==========================================
    robot = universal_robots.UniversalRobotsUR10E(name='UR10e')

    # ==================== Visualization (Optional) =============================
    # Live: subscribes to the robot's state topic and redraws as it moves.
    robot.visualize_rerun(live=True)

    try:
        #===================== Connect Robot ==========================================
        if ip:
            robot.connect(ip=ip)
        elif prim_path:
            robot.connect(simulation_prim_path=prim_path)
            robot.set_joint_positions(robot.default_joint_configuration)

        # ==================== Run Skill ============================================
        # Joint acceleration [deg/s^2] for joint moves called without one
        robot.set_joint_acceleration(acceleration=40)
        logger.info("Default joint acceleration set to 40 deg/s^2.")

        #===================== Move With Defaults ==========================================
        target_joint_positions = list(robot.get_joint_positions())
        target_joint_positions[0] += 20  # +20 deg on joint 0

        # Called without speed/acceleration, so the defaults set above are used
        robot.set_joint_positions(joint_positions=target_joint_positions)
        logger.success(f"Moved to target joint positions: {target_joint_positions}")
    except (ConnectionError, OSError) as e:
        logger.error(f"Error occurred: {e}")
    finally:
        robot.disconnect()
        robot.shutdown()


if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Set the default joint acceleration and move with it.")
    parser.add_argument("--ip", type=str, default=None,
                         help="UR robot IP address for real hardware, e.g. 192.168.1.100")
    parser.add_argument("--prim_path", type=str, default=None,
                         help='Isaac Sim articulation prim path, e.g. "/World/ur10e"')
    args = parser.parse_args()

    main(ip=args.ip, prim_path=args.prim_path)

Running the Example

Virtual

python set_joint_acceleration.py

Isaac Sim

python set_joint_acceleration.py --prim_path /World/ur10e

Real

python set_joint_acceleration.py --ip 192.168.1.100

For all options:

python set_joint_acceleration.py --help

Parameter Configuration

Parameter	Type	Default	Description
acceleration	float	required	New default joint acceleration in deg/s². Must be finite and positive.

Returns

Type	Description
None	The default is stored on the robot and used by Set Joint Positions and Set Cartesian Pose in Joint Space.

Raises

Exception	Condition
TypeError	acceleration is not a number
ValueError	acceleration is not finite and positive

How to Tune the Parameters

Applies to Set Joint Positions and Set Cartesian Pose in Joint Space when they are called without an explicit acceleration; an explicit value passed to the motion still wins. Start conservatively while validating a new path, then raise the default once the motion is confirmed clear.

Where to Use the Skill

• Program-wide defaults - Set the speed once instead of passing it to every move.
• Commissioning - Slow everything down while testing a new cell.

When Not to Use the Skill

• One move needs a different value - pass it directly to the motion call.
• You want to interrupt a move - use Stop Joint Motion or Stop Cartesian Motion.